Ok kiddo, so a long time ago there was a country called Germany, but it was split into two parts. One part was called East Germany and the other part was called West Germany. Each part had its own government and even their own football teams.
The East Germany national football team was made up of players from East Germany and they played against other countries' football teams. They wore white and blue uniforms and their logo had a bird on it.
But eventually, the two parts of Germany became one country again and the East Germany national football team stopped playing. One reason for this was that many of their best players started playing for the new and bigger German football team.
So, in short, the East Germany national football team was a team from a country that was split in two, and they played football games against other countries. But when Germany became one country again, they stopped playing.